Abstract: A semiconductor integrated optical device includes: a supporting base including semi-insulating semiconductor; a first photoelectric convertor having first photodiode mesas; a second photoelectric convertor having second photodiode mesas; a first 90° optical hybrid having at least one first multimode waveguide mesa; a second 90° optical hybrid having at least one second multimode waveguide mesa; an optical divider mesa; first and second input waveguide mesas coupling the first and second 90° optical hybrids with the optical divider mesa, respectively; a conductive semiconductor region disposed on the supporting base, the conductive semiconductor region mounting the first photodiode mesas, the second photodiode mesas, the first multimode waveguide mesas, the second multimode waveguide mesas, and the optical divider mesa; a first island semiconductor mesa extending between the first and second multimode waveguide mesas; and a first groove extending through the first island semiconductor mesa and the conductive

Abstract: A receiver optical module that receives an optical signal and generating an electrical signal corresponding to the optical signal is disclosed. The module includes a photodiode (PD), a sub-mount, a pre-amplifier, and a stem. The sub-mount, which is made of insulating material, mounts the PD thereon. The pre-amplifier, which receives the photocurrent generated by the PD, mounts the PD through the sub-mount with an adhesive. The pre-amplifier generates an electrical signal corresponding to the photocurrent and has signal pads and other pads. The stem, which mounts the pre-amplifier, provides lead terminals wire-bonded with the signal pads of the pre-amplifier. The signal pads make distances against the sub-mount that are greater than distances from the other pads to the sub-mount.

Abstract: A process for forming a nitride semiconductor device is disclosed. The resulting semiconductor device includes a semiconductor stack with a top layer containing gallium (Ga) and nitrogen (N), electrodes of a source, a gate and a drain provided on the semiconductor stack, and a silicon nitride (SiN) film provided on the GaN layer between the drain electrode and the gate electrode but apart from the gate electrode. The SiN film has a silicon rich composition with a composition ratio of Si/N that is greater than ¾ and substantial oxygen contents.

Abstract: A method of controlling an optical transmitter comprising a determining step, a dividing step and a determining step. In the determining step, a full range of an optical signal output from a light-generating device is determined by setting an upper and a lower limit thereof by keeping power of a continuous wave (CW) light constant and varying an electrical driving signal, the optical signal having 2n optical levels where n is an integer. In the dividing step, the full range of the optical signal is divided into sub-ranges each between the neighbor optical levels including the upper limit and the lower limit of the full range, the sub-ranges having preset ratios. In the determining step, electrical levels of the electrical driving signal are determined based on a non-linear transfer characteristic of the light-generating device between the electrical driving signal supplied thereto and the optical signal output therefrom.

Abstract: An MIM capacitor of a semiconductor device is configured to include a dielectric layer between a lower electrode and an upper electrode, and a floating electrode provided in the dielectric layer, extended in parallel to the upper electrode and the lower electrode, and not electrically connected from any one of the lower electrode and the upper electrode is included.

Abstract: A wavelength de-multiplexing system that receives a wavelength multiplexed signal and generates electrical signals corresponding to the optical signals is disclosed. The optical receiver module includes a lens, a lens unit, and an optical de-multiplexer (O-DeMux). The lens converts the wavelength multiplexed signal into a quasi-collimated beam. The lens unit narrows a diameter of the quasi-collimated beam. The O-DeMux de-multiplexes the narrowed quasi-collimated beam coming from the lens unit by wavelength selective filters (WSFs) each having optical distances from the lens unit different from each other.

Abstract: A method includes steps of: acquiring a target wavelength; acquiring a drive condition of a wavelength tunable laser diode; driving the wavelength tunable laser diode based on the drive condition; acquiring a measured value of the first current measured by a first photodetector, a measured value of a second current measured by a second photodetector and a measured value of the drive condition; determining the measured value of the first current as a first target value; calculating a second target value of the second current from the measured value of the drive condition and the target value of the first current; and coinciding a ratio of the measured value of the first current with respect to the measured value of the second current, to a ratio of the first target of the first current with respect to the second target of the second current, by changing the drive condition.

Abstract: A method of manufacturing an electronic component having an electrode at an end portion thereof is disclosed. The method includes placing a jig on a heater block, wherein the jig includes a path inclined with respect to a pedestal including a placement surface and extending toward the pedestal; placing an electronic component main body having the electrode on the placement surface with the electrode facing the path; rolling a ball-shaped solder in the path to reach the electrode; and melting the solder through the pedestal to attach the molten solder to the electrode.

Abstract: A high electron mobility transistor (HEMT) includes a semiconductor layer on a substrate; an insulating film on the semiconductor layer; a gate electrode in contact with a surface of the semiconductor layer through an opening in the insulating film; and a conductive film provided between the insulating film and a portion of the gate electrode at peripheries of the opening. The insulating film and the conductive film are made of respective materials containing silicon (Si). The gate electrode includes a Schottky metal in contact with the semiconductor layer and a cover metal provided on the Schottky metal. The Schottky metal covers the conductive film thereunder.

Abstract: A photodiode (PD) device that monolithically integrates a PD element with a waveguide element is disclosed. The PD device includes a conducting layer with a first region and a second region next to the first region, where the PD element exists in the first region, while, the waveguide element exists in the second region and optically couples with the PD element. The waveguide element includes a core layer and a cladding layer on the conducting layer, which forms an optical confinement structure. The PD element includes an absorption layer on the conducting layer and a p-type cladding layer on the absorption layer, which form another optical confinement structure. The absorption layer has a length at least 12 ?m measured from the interface against the core layer.

Abstract: Test equipment that is able to concurrently evaluate two or more optical modules each processing a wavelength multiplexed signal that multiplexes optical signals attributed to wavelengths different from each other. The test equipment provides a first test station and a second test station. After selecting one of the wavelengths, the first test station performs a first evaluation for an optical signal attributed to the one of the wavelengths and coming from the first optical module, and the second station concurrently performs a second evaluation for an optical single with the one of the wavelengths and coming from the second optical module. Thereafter, the first test station performs the first evaluation for the optical signal coming from the second optical module, while, the second test station performs the second evaluation for the optical signal coming from the first optical module.

Abstract: A process for forming a nitride semiconductor device is disclosed. The resulting semiconductor device includes a semiconductor stack with a top layer containing gallium (Ga) and nitrogen (N), electrodes of a source, a gate and a drain provided on the semiconductor stack, and a silicon nitride (SiN) film provided on the GaN layer between the drain electrode and the gate electrode but apart from the gate electrode. The SiN film has a silicon rich composition with a composition ratio of Si/N that is greater than 3/4 and substantial oxygen contents.

Abstract: A manufacturing method for an optical semiconductor device includes: forming a first semiconductor layer; forming a first mask pattern on the first semiconductor layer in a first area where an electro absorption type modulator is formed; forming an evenness along the first direction on the first semiconductor layer; forming a second semiconductor layer on the unevenness; and forming an optical waveguide layer on the second semiconductor layer. The first mask pattern includes a first pattern in the first area and a second pattern in a second area where a DFB laser is formed, the first pattern including a first opening pattern and a first cover pattern, and the second pattern including a second opening pattern and a second cover pattern, and a ratio of the first opening pattern to the first cover pattern is different from that of the second opening pattern to the second cover pattern.

Abstract: A semiconductor device manufacturing method includes forming an organic insulating layer on a semiconductor on which metal wiring is provided, the organic insulating layer having an opening to expose part of the metal wiring, forming a seed metal covering the part of the metal wiring exposed from the opening, and an inside face and an around portion of the opening of the organic insulating layer, forming a mask covering an edge of the seed metal and exposing part of the seed metal formed in the opening, and forming a barrier metal on the seed metal exposed from the mask by electroless plating. The mask includes an organic material or an inorganic dielectric material.

Abstract: A semiconductor device includes a substrate, an active region and an inactive region surrounding the active region, a gate electrode, a drain electrode and a source electrode on the active region, a drain interconnection including a drain finger and a drain bar, and a source interconnection including a source finger and a source bar. The source bar is located on an opposite side of the drain bar across the active region in a first direction. The source electrode includes a first side facing the drain bar in the first direction and a first depression in a middle of the first side. A first depth of the first depression in the first direction is equal or more than a first interval between the drain bar and the first side in the first direction.

Abstract: A light emitting module including a semiconductor light emitting element, a first lens, a second lens, and an optical fiber stub, is disclosed. The first lens collimates light output from the semiconductor light emitting element. The second lens is a meniscus lens and condenses the collimated light to the optical fiber stub. A light entering surface of the second lens has a cross-sectional shape in which an increase rate of a curvature radius is zero or more. A light exiting surface of the second lens includes a first region and a second region. The first region has a cross-sectional shape in which a sign of the increase rate of the curvature radius is positive. The second region surrounds the first region and has a cross-sectional shape in which a sign of the increase rate of the curvature radius is negative.

Abstract: A photodiode (PD) device that monolithically integrates a PD element with a waveguide element is disclosed. The PD device includes a conducting layer with a first region and a second region next to the first region, where the PD element exists in the first region, while, the waveguide element exists in the second region and optically couples with the PD element. The waveguide element includes a core layer and a cladding layer on the conducting layer, which forms an optical confinement structure. The PD element includes an absorption layer on the conducting layer and a p-type cladding layer on the absorption layer, which form another optical confinement structure. The absorption layer has a length at least 12 ?m measured from the interface against the core layer.

Abstract: A amplifier device includes an amplifier, a coupling circuit, and a filter circuit. The amplifier amplifies a high frequency signal, and outputs to signal output ports the high frequency signal. The coupling circuit is provided side-by-side with the amplifier in a first direction on a substrate, connected to the signal output ports, and configured to couple output signals and output one output signal to an output terminal. The filter circuit is provided on the substrate and connected to the coupling circuit, and configured to reduce third-order IMD included in the one output signal. The one output signal is output from a middle of the substrate in a second direction intersecting with the first direction, and the filter circuit is arranged next to an edge of the substrate in the second direction, and arranged next to an edge of the substrate on the output terminal side in the first direction.

Abstract: A coherent receiver comprising: a signal port receiving the signal light that has two polarization components at right angles each other; a polarization dependent beam splitter (PBS) that splits the signal light into two portions depending on the polarizations contained in the signal light; a beam splitter (BS) that splits the local light into two portions; a multi-mode interference (MMI) device that interferes between one of the two portions of the signal light and one of the two portions of the local light; optical components provided between the PBS and the MMI device; and wherein the PBS splitting a first wavelength range of the signal light and a second wavelength range outside the first wavelength range.

Abstract: A process of forming a light-receiving device type of avalanche photodiode (APD) is disclosed. The process includes steps of: (1) growing semiconductor layers on a semiconductor substrate, the semiconductor layers providing a first area on a top thereof; (2) thermally diffusing impurities within the semiconductor layers in a second area outside of the first area so as to leave a roughed surface in a top of the second area, the impurities laterally diffusing to form an diffusion edge locating inside of the first area; and (3) removing the semiconductor layers including the roughed surface thereof in the second area to form a mesa in the first area, the mesa including the diffusion edge in a periphery thereof but excluding the roughed surface.